McDonnell Douglas DC-10

The initial DC-10-10, powered by three GE CF6s, has two main landing gears.

DC-10-10

The DC-10-10 is the initial passenger version introduced in 1971, produced from 1970 to 1981. The DC-10-10 was equipped with GE CF6-6 engines, which was the first civil engine version from the CF6 family. A total of 122 were built.[24]

DC-10-10CF

The -10CF is a convertible passenger and cargo transport version of the -10 . Eight were built for Continental Airlines and one for United Airlines.[24]

DC-10-15

The -15 variant was designed for use at hot and high airports. The series 15 is basically a -10 fitted with higher-thrust GE CF6-50C2F (derated DC-10-30 engines) powerplants.[25] The −15 was first ordered in 1979 by Mexicana and Aeroméxico. Seven were completed between 1981 and 1983.[26]

The heavier DC-10-30 has an additional centre landing gear

The heavy DC-10-40 is powered by three Pratt & Whitney JT9Ds

DC-10-30

A long-range model and the most common model produced. It was built with General Electric CF6-50 turbofan engines and larger fuel tanks to increase range and fuel efficiency, as well as a set of rear center landing gear to support the increased weight. It was very popular with European flag carriers. A total of 163 were built from 1972 to 1988 and delivered to 38 different customers.[27] The model was first delivered to KLM and Swissair on November 21, 1972 and first introduced in service on December 15, 1972 by the latter.

DC-10-30CF

The convertible cargo/passenger transport version of the -30. The first deliveries were to Overseas National Airways and Trans International Airlines in 1973. A total of 27 were built.[28]

DC-10-30ER

The extended-range version of the -30. The -30ER aircraft has a higher maximum takeoff weight of 590,000 lb (267,600 kg), is powered by three GE CF6-50C2B engines each producing 54,000 lbf (240 kN) of thrust and is equipped with an additional fuel tank in the rear cargo hold.[29][30] It has an additional 700 mi of range to 6,600 mi (5,730 nmi, 10,620 km). The first of this variant was delivered to Finnair in 1981. A total of six were built and five −30s were later converted to −30ERs.

DC-10-30AF

Also known as the DC-10-30F. This was the all freight version of the -30. Production was to start in 1979, but Alitalia did not confirm its order then. Production began in May 1984 after the first aircraft order from FedEx. A total of 10 were built.[31]

DC-10-40

The first long-range version fitted with Pratt & Whitney JT9D engines. Originally designated DC-10-20, this model was renamed DC-10-40 after a special request from Northwest Orient Airlines as the aircraft was much improved compared to its original design, with a higher MTOW (on par with the Series 30) and more powerful engines. The airline's president wanted to advertise he had the latest version.[32][33] The company also wanted its aircraft to be equipped with the same engines as its Boeing 747s for fleet commonality.[34] Northwest Orient Airlines and Japan Airlines were the only airlines to order the Series 40 with 22 and 20 aircraft, respectively. Engine improvements led to the DC-10-40s delivered to Northwest featuring Pratt & Whitney JT9D-20 engines producing 50,000 lbf (222 kN) of thrust and a MTOW of 555,000 lb (251,815 kg). The -40s for Japan Airlines were equipped with P&W JT9D-59A engines that produced a thrust of 53,000 lbf (235.8 kN) and a MTOW of 565,000 lb (256,350 kg).[35] 42 were built from 1973 to 1983.[36] Externally, the DC-10-40 can be distinguished from the -30 series by a slight bulge near the front of the nacelle for the #2 (tail) engine.

The DC-10 Twin concept

DC-10-20

A proposed version of the DC-10-10 with extra fuel tanks, 3-ft (0.9 m) extensions on each wingtip and a rear center landing gear. It was to use Pratt & Whitney JT9D-15 turbofan engines, each producing 45,500 lbf (203 kN) of thrust, with a maximum takeoff weight of 530,000 lb (240,400 kg). But engine improvements led to increased thrust and increased takeoff weight.[35] Northwest Orient Airlines, one of the launch customers for this longer-range DC-10 requested the name change to DC-10-40.[32]

DC-10-50

A proposed version with Rolls-Royce RB211-524 engines for British Airways. The order never came and the plans for the DC-10-50 were abandoned after British Airways ordered the Lockheed L-1011-500 instead.[37]

DC-10 Twin

Two-engine designs were studied for the DC-10 before the design settled on the three-engine configuration. Later a shortened DC-10 version with two engines was proposed against the Airbus A300.[38]

The KC-10 Extender, an USAF aerial tanker

The KC-10 Extender is a military version of the DC-10-30CF for aerial refueling. The aircraft was ordered by the U.S. Air Force and delivered from 1981 to 1988. A total of 60 were built.[39]

The KDC-10 is an aerial refueling tanker for the Royal Netherlands Air Force. These were converted from civil airliners (DC-10-30CF) to a similar standard as the KC-10. Also, commercial refueling companies Omega Aerial Refueling Services[40][41] and Global Airtanker Service[42][43] operate two KDC-10 tankers for lease. Four have been built.

The DC-10 Air Tanker is a DC-10-based firefighting tanker aircraft, using modified water tanks from Erickson Air-Crane.

The MD-10 has a MD-11-inspired two-crew glass cockpit

The MD-10 is a glass cockpit upgrade to the DC-10 with the re-designation to MD-10. The upgrade included an Advanced Common Flightdeck used on the MD-11 and was launched in 1996.[44] The new cockpit eliminated the need for the flight engineer position and allowed common type rating with the MD-11. This allows companies such as FedEx Express, which operate both the MD-10 and MD-11, to have a common pilot pool for both aircraft. The MD-10 conversion now falls under the Boeing Converted Freighter program where Boeing's international affiliate companies perform the conversions.[45]

The DC-10 was designed with cargo doors that opened outward instead of conventional inward-opening "plug-type" doors. Using outward-opening doors allowed the DC-10's cargo area to be completely filled, since the door was not occupying usable interior space when open. To secure the door against the outward force from the pressurization of the fuselage at high altitudes, outward-opening doors must use heavy locking mechanisms. In the event of a door lock malfunction, there is great potential for explosive decompression.[66]

On June 12, 1972, American Airlines Flight 96 lost its aft cargo door in flight above Windsor, Ontario. Before takeoff, an airport employee had forced the door shut, and although the door appeared to be securely locked, the internal locking mechanism was not fully engaged. When the aircraft reached approximately 11,750 feet (3,580 m) in altitude, the door blew out, causing an explosive decompression that collapsed the cabin floor.[67] The collapse cut or impeded many of the control cables to the empennage, leaving the pilots with very limited control of the aircraft.[68][68][69] The crew performed an emergency landing by using the ailerons, right elevator, some limited rudder trim, and asymmetrical thrust of the wing engines.[70] All 67 passengers evacuated safely.[71]

U.S. National Transportation Safety Board (NTSB) investigators found the cargo door design to be dangerously flawed, as the door could be closed without the locking mechanism fully engaged, and this condition was not apparent from visual inspection of the door nor from the cargo-door indicator in the cockpit. The NTSB recommended that the cargo door be modified to make it readily apparent to baggage handlers when it was not secured, and also recommended that vents be installed in the cabin floor, so that in case of an explosive decompression, the pressure difference between the cabin and cargo bay could quickly equalize without damaging other aircraft systems.[67] Although many carriers voluntarily modified the cargo doors, no airworthiness directive was issued, due to a gentlemen's agreement between the head of the FAA, John H. Shaffer, and the head of McDonnell Douglas's aircraft division, Jackson McGowen. McDonnell Douglas made some modifications to the cargo door, but the basic design remained unchanged, and problems persisted.[67]

On March 3, 1974, in an accident circumstantially similar to American Airlines Flight 96, a cargo-door blowout caused Turkish Airlines Flight 981 to crash near Ermenonville, France.[67] All 346 people on board died[72] in one of the deadliest air crashes of all time.[73] The cargo door of Flight 981 had not been fully locked, though it appeared so to both cockpit crew and ground personnel. The Turkish aircraft had a seating configuration that exacerbated the effects of decompression, and as the cabin floor collapsed into the cargo bay, control cables were severed and the aircraft became uncontrollable.[67] Crash investigators found that the DC-10's relief vents were not large enough to equalize the pressure between the passenger and cargo compartments during explosive decompression.[72] Following this crash, a special subcommittee of the United States House of Representatives investigated the cargo-door issue and the FAA's certification of the original design.[74] An airworthiness directive was issued, and all DC-10s underwent mandatory door modifications.[74] The DC-10 experienced no more major incidents related to its cargo door after FAA-approved changes were made.[67]

On May 25, 1979, American Airlines Flight 191 crashed immediately after takeoff from Chicago's O'Hare Airport.[75] As the airliner rotated during its takeoff roll, the left engine and pylon assembly swung upward over the top of the wing, severing critical hydraulic lines before falling away. The leading edge slat actuators lost hydraulic pressure and the slats retracted due to aerodynamic forces, causing the left wing to stall. This condition, combined with asymmetric thrust due to the missing engine, caused the aircraft to rapidly roll to the left, sharply descend, and crash, killing all 271 people on board and two individuals on the ground.[76] The loss of Flight 191 remains the deadliest single-aircraft aviation accident in U.S. history. The crash and its aftermath were widely covered by the media and dealt a severe blow to the DC-10's reputation and sales.

Following the crash, the FAA withdrew the DC-10's type certificate on June 6, 1979, grouding all 138 U.S.-registered DC-10s along with those from other nations with bilateral agreements with the United States, and banning all other DC-10s from U.S. airspace. Even ferry flying within U.S. airspace was forbidden except to allow foreign air carriers to return their DC-10s to overseas maintenance bases.[77] These measures were rescinded five weeks later on July 13, 1979, after modifications were made to the slat actuation and position systems, along with stall warning and power supply changes.[78][79]

NTSB officials discovered that American Airlines mechanics had removed the engine and its pylon as a unit, rather than removing the engine from the pylon before removing the pylon from the wing, as recommended by McDonnell Douglas. The non-standard procedure resulted in inadvertent structural damage, which the NTSB deemed to have caused the engine separation and the subsequent crash. It was later discovered that this short-cut procedure, believed to save many man-hours, was being used by both American Airlines and Continental Airlines, although McDonnell Douglas had advised against it.[78] In November 1979, the Federal Aviation Administration (FAA) fined American Airlines $500,000 and Continental Airlines $100,000 for using this incorrect maintenance procedure.[78][80]

The Flight 191 crash highlighted a major deficiency in the DC-10 design: its lack of a locking mechanism to maintain the position of the leading-edge slats in the event of a hydraulic or pneumatic actuation failure.[78] When the engine and pylon assembly pulled up and over the wing, it severed electrical wiring in the wing, thus rendering vital warning instruments in the cockpit inoperative.

In the wake of the grounding, the FAA convened a safety panel under the auspices of the National Academy of Sciences, to evaluate the design of the DC-10 and the U.S. regulatory system in general. The panel's report, published in June 1980, found "critical deficiencies in the way the Government certifies the safety of American-built airliners". This conclusion was echoed nearly 40 years later in the inquiries into the 2019 grounding of the Boeing 737 MAX.[81]

On July 19, 1989, United Airlines Flight 232 crashed at Sioux City, Iowa after the tail engine suffered an uncontained engine failure earlier in the flight, damaging all three hydraulic systems and rendering the hydraulic flight controls inoperable. The flight crew, led by Captain Al Haynes and assisted by DC-10 flight instructor flying as a passenger (Dennis E. "Denny" Fitch), performed an emergency landing by constantly adjusting the thrust of the remaining two engines. The crew managed to fly the aircraft onto the runway in a partially controlled manner; 185 people on board survived, but 111 others died and the aircraft was destroyed during the crash landing.[82]

The DC-10 included no cable backup for the hydraulic-powered flight controls because it was considered nearly impossible for all three hydraulic systems to fail, and the control surfaces were too large to be moved without hydraulic assistance. However, all three systems were in such close proximity under the tail engine that the engine failure ruptured all of them, resulting in total loss of control to the elevators, ailerons, spoilers, horizontal stabilizer, rudder, flaps and slats.[82]

Following the accident, hydraulic fuses were installed in the #3 hydraulic system in the area below the tail engine on all DC-10 aircraft to ensure that sufficient control capability remained if all three hydraulic system lines should be damaged in this area. It is still possible to lose all three hydraulic systems elsewhere. This nearly happened to a cargo airliner in 2002 during takeoff when a main-gear tire exploded in the wheel well. The damage in the left wing area caused total loss of pressure from the #1 and the #2 hydraulic systems. The #3 system was dented but not penetrated.[83]

Other notable accidents are:

• November 3, 1973: National Airlines Flight 27, a DC-10-10 cruising at 39,000 feet, experienced an uncontained failure of the right (number 3) engine. One cabin window separated from the fuselage after it was struck by debris flung from the exploding engine. The passenger sitting next to that window was killed and ejected from the aircraft. The crew initiated an emergency descent, and landed the aircraft safely.[84]
• December 17, 1973: Iberia Airlines Flight 933 crashed and struck the ALS system at Boston Logan International Airport which collapsed the front landing gear. All 168 passengers and crew survived. This is the first hull loss of a DC-10 aircraft.
• November 12, 1975: ONA Flight 032, a DC-10 on a ferry flight struck a heavy flock of seagulls while on its takeoff roll from JFK International Airport, New York. The captain aborted below V1 speed, but the #3 engine exploded, causing a partial braking failure. The landing gear collapsed and fire eventually destroyed the plane. All 139 ONA employees on board survived. Two were seriously injured, while 30 others had minor injuries.[85]
• January 2, 1976: An ONA DC-10 experienced an undershoot on a short runway in Istanbul, Turkey. The aircraft touched the ground and crash landed, then a fire in the #1 engine started. The aircraft was destroyed. All passengers survived.[86]
• March 1, 1978: Continental Airlines Flight 603, a DC-10-10, began its take-off from Los Angeles International Airport. Approaching V1 in the takeoff roll, the recapping tread of the No. 2 tire on the left main landing gear separated from the tire and the resulting overload caused that tire to blow out. That in turn, imposed an overload on the No. 1 tire on the same axle, resulting in a second blowout almost immediately after the first blowout. Shrapnel from the rims of the failed tires then damaged the No. 5 tire on the left main gear, causing it to also blow out. The blowouts ruptured a fuel tank, which combined with the excessive heat from the aborted take off maneuver, resulted in a massive fire. Two passengers were killed in the ensuing evacuation and two died later from injuries sustained in the accident.
• October 31, 1979: Western Airlines Flight 2605, a DC-10-10, collided with construction equipment after landing on a closed runway at Mexico City International Airport, killing 72 of the 88 people on board and one person on the ground. The crash was caused by failure to follow proper landing guidelines in consideration of the fog on the runway.[87]
• November 11, 1979: Aeromexico Flight 945 entered a sustained stall while climbing through 29,800 ft, to its assigned cruise altitude of 31,000 ft, over Luxembourg, Europe. The flight crew failed to monitor their flight instruments, so they did not immediately recognize that the plane was in a stalled condition. Instead, they blamed the heavy buffeting on the #3 engine, which they shut down, while continuing to hold the nose up. The plane continued to descend for one minute in a fully stalled condition, until the pilots lowered the nose and began a proper stall recovery procedure, which was completed at 18,900 ft. The #3 engine was then restarted, the declaration of emergency was canceled and the flight continued to Miami, Florida. Ground inspection revealed four feet missing from each of the outboard elevator tips, including the balance weights. The NTSB concluded that the sustained stall buffeting produced a dynamic structural overload on the elevator, which resulted in the failure of the elevator tips and balance weights. Further, the NTSB concluded that the autopilot had improperly been placed in vertical speed mode. That forced the AP to keep increasing the angle of attack to maintain the preselected vertical speed number, because maximum available engine thrust declined (normally) with increasing altitude. That caused the airspeed to fall below the stall speed of the aircraft.[88]
• November 28, 1979: Air New Zealand Flight 901, DC-10-30 ZK-NZP, crashed into Mount Erebus on Ross Island, Antarctica during a sightseeing flight over the continent, killing all 257 on board. The accident was caused by the flight coordinates being altered without the flight crew's knowledge, combined with unique Antarctic weather conditions.[89]
• January 12, 1981: Garuda Indonesia DC-10-30 PK-GIB overran the runway on landing at Hasanuddin Airport, Ujung Pandang, Sulawesi, Indonesia and was substantially damaged.[90]
• January 23, 1982: World Airways Flight 30, DC-10-30CF registration N113WA, overran the runway at Boston Logan International Airport. All 12 crew survived, but two of the 200 passengers were never found.[91]
• September 13, 1982: Spantax Flight 995, DC-10-30CF EC-DEG, was destroyed by fire after an aborted take-off at Málaga, Spain. A total of 50 passengers were killed and 110 injured due to the flames.
• May 21, 1988: American Airlines Flight 70, DC-10-30 N136AA, overran Runway 35L at Dallas/Fort Worth International Airport after the flight crew attempted a rejected takeoff. The aircraft continued to accelerate for several seconds before slowing, and ran 1,100 feet (335 m) past the runway threshold, collapsing the nose landing gear. 2 crew were seriously injured and the remaining 12 crew and 240 passengers escaped safely; the aircraft was severely damaged and was written off. The accident was attributed to a shortcoming in the original design standards; there had been no requirement to test whether partially worn brake pads could stop the aircraft during a rejected takeoff, and 8 of the 10 worn pad sets had failed.[92][93]
• July 27, 1989: Korean Air Flight 803, DC-10-30 HL7328, crashed short of the runway in bad weather while trying to land at Tripoli, Libya. A total of 75 of the 199 on board plus another 4 people on the ground were killed in the accident.[94]
• September 19, 1989: UTA Flight 772, DC-10-30 N54629, crashed in the Ténéré Desert in Niger following an in-flight bomb explosion, claiming the lives of all 170 on board.
• December 21, 1992: Martinair Flight 495, DC-10-30CF PH-MBN, crashed while landing in bad weather at Faro, Portugal killing 54 passengers and crew.[95][96]
• April 14, 1993: The pilot of American Airlines Flight 102, DC-10-30 N139AA, lost directional control during a crosswind landing at Dallas/Fort Worth International Airport. The aircraft slid off Runway 17L, collapsing the nose landing gear and tearing off the left-hand engine and much of the left wing. 2 passengers suffered serious injuries while using the evacuation slides to escape from the steeply tilted fuselage; the remaining 187 passengers and 13 crew evacuated safely. The aircraft was written off.[97][98][99]
• April 7, 1994: Federal Express Flight 705, DC-10-30 N306FE, experienced an attempted hijacking. FedEx employee Auburn Calloway tried to hijack the aircraft with the intention of crashing it, but the crew fought him off and returned to Memphis. The co-pilot used a number of aerobatic maneuvers to assist his colleagues in fighting off the hijacker.[100]
• June 13, 1996: Garuda Indonesia Flight 865, DC-10-30 PK-GIE, had just taken off from Fukuoka Airport, Japan when a high-pressure blade from engine #3 separated. The aircraft was just a few feet above the runway, and the pilot decided to abort the take-off. Consequently, the DC-10 skidded off the runway and came to a halt 1,600 ft (490 m) past it, losing one of its engines and its landing gear. Three passengers perished in the accident.
• July 25, 2000: Continental Airlines Flight 55, operated by a DC-10-30 registered as N13067, shed a strip of metal from the thrust reverser cowl door of the number 3 engine, which landed on the runway at Charles de Gaulle Airport upon take off. Minutes later, Air France Flight 4590, operated by a Concorde, ran over the metal strip at near V1 speed, bursting a tire and causing a fuel tank to rupture and burst into flames. The Concorde's pilots attempted to keep control of the aircraft, but it stalled and crashed. The strip of metal was traced to third-party replacement parts not approved by the Federal Aviation Administration.[101]
• October 28, 2016: FedEx Express Flight 910, MD-10-10F N370FE, landing gear collapsed after landing at Fort Lauderdale–Hollywood International Airport. This started a fire that damaged the airplane's port wing. The crew members escaped without injuries.[102]